Apparatus for holding a rotary tool

ABSTRACT

Apparatus for holding a rotary tool, such as a roof drill or a roof bolt wrench, in an upwardly opening drive socket rotatable on a generally vertical axis in a drill box at the end of a pivot boom of a mine roof drill and bolter. The apparatus includes a support adapted to be bolted to the drill box, and at least one retaining member carried by the support for movement between a retracted position permitting insertion of the lower end of the tool in the drive socket and removal of the lower end of the tool therefrom and an operative position in which the retaining member overlies a lower end portion of the tool to restrict upward movement of the tool, with means for effecting movement of the retaining member between its retracted and operative positions.

United States Patent 1 Bucelluni Sept. 4, 1973 APPARATUS FOR HOLDING A ROTARY TOOL [75] Inventor: Guido Bucelluni, Taylorville, Ill.

[73] Assignee: Lee-Norse Company, Charleroi, Pa.

[22] Filed: Jan. 28, 1972 [21] Appl. No.: 221,581

[52] US. Cl. 308/3.9

[51] Int. Cl. Fl6c 21/00 [58] Field of Search 308/39; 279/44, 279/4, 19.1, 19.2

[56] References Cited UNITED STATES PATENTS 3,246,547 4/1966 O'Neill 308/39 2,734,723 2/1956 Larceny. 308/39 2,523,512 9/1950 Nast 308/39 3,441,323 4/1969 Vincent 308/39 3,612,190 4/1970 Wills 308/39 3,206,259 9/1965 Curtis 308/39 2,727,725 12/1955 Samhammer 308/39 Primary ExaminerCharles J. Myhre Assistant ExaminerR. H. Lazarus Attorney-David W. Tibbott and Robert R. Paquin [5 7 ABSTRACT Apparatus for holding a rotary tool, such as a roof drill or a roof bolt wrench, in an upwardly opening drive socket rotatable on a generally vertical axis in a drill box at the end of a pivot boom of a mine roof drill and bolter. The apparatus includes a support adapted to be bolted to the drill box, and at least one retaining member carried by the support for movement between a retracted position permitting insertion of the lower end of the tool in the drive socket and removal of the lower end of the tool therefrom and an operative position in which the retaining member overlies a lower end portion of the tool to restrict upward movement of the tool, with means for effecting movement of the retaining member between its retracted and operative positions.

12 Claims, 9 Drawing Figures 1' i 1 I1 71 72 I 22 1 2| )4 11' id 12.. ii

PATENTEUSEP 4192a 3356369 FIG.1

IEP

PATENTED SE? 4 i975 SHEET 2 BF 4 APPARATUS FOR HOLDING A ROTARY TOOL BACKGROUND OF THE INVENTION This invention relates to safety apparatus for underground mining machinery, and is particularly concerned with a retainer for holding a rotary tool (e.g., a drill or a roof bolt wrench) in a drive socket of a roof drill and bolter for protecting miners against injury by preventing the tool from jumping out of the drive socket as the tool is rotary-driven.

The invention is useful in carrying out techniques for underground mining without the use of overhead shoring supports for bracing the mine roof where the geological formations of the mine roof permits. This shoreless mining involves drilling vertical holes in the mine roof, and inserting roof bolts in the holes. These roof bolts expand on tightening, become wedged in the holes, and on further tightening compress the laminated strata of the mine roof to form a beam or arch which is self-supporting.

The holes for the roof bolts are drilled by roof drill and bolters such as those manufactured by applicants assignee, Manson Machine Company, of Taylorville, Illinois. These roof drill and bolters are four-wheel vehicles movable in the mine from one drilling position to another carrying one or more pivotally mounted drill booms. Each drill boom has a hydraulically driven drill motor at its outer end for driving a rotary drill socket in which a rotary tool (e.g., a drill or a roof bolt wrench) is placed. The drill boom is swingable between a lowered position in which its outer end is adjacent the floor of the mine and a raised position in which its outer end is adjacent the roof of the mine, being movable from its lowered position to its raised position at a controlled rate to feed the drill into the mine roof as the hole is drilled. After a hole has been drilled, the drill is backed out of the hole and removed from the drive socket. A roof bolt is theninserted into the hole and is tightened by a roof bolt wrench which is rotary-driven by the drive socket of the roof drill and bolter.

Occasionally, a drill driven by the roof drill and bolter will break, causing the drill to fly out of its drive socket. Or the drill may be inadvertently driven at high speed while it is out of working engagement with the mine roof causing the drill to whip and fly out of the drive socket. Nearby miners are in danger of being severely injured by a drill flying out of its socket. The intent of the Federal Coal Mine Health and Safety Act of 1969" is that every effort should be made to make mine conditions and mining practices as safe as possible for the coal miners, and the apparatus of this invention has been developed for making the operation of roof drills and bolters safer for miners than in the past.

SUMMARY OF THE INVENTION Among the several objects of this invention may be noted the provision of a retainer for holding a rotary tool in the rotary drive socket of a roof drill and bolter in the event the tool breaks or is rotated at high speed out of working engagement with the mine roof, to prevent the tool from flying out of the socket for the safety of miners working nearby; the provision of such a retainer which permits the rapid changing of tools driven by the rotary drive socket; the provision of such a retainer which enables a rotary roof drill to be forcibly withdrawn from a roof bolt hole drilled in the mine roof by lowering the pivot boom of the roof drill and bolter;

the provision of such a retainer which journals the rotary tool in such manner as substantially to reduce the tendency of the tool to whip" in the event the tool is rotated at high speed when it is not in working engagement with the mine roof; and the provision of such a retainer which is of simple and rugged construction and which is easy to operate.

In general, a retainer of this invention for holding a rotary tool, such as a roof drill or a roof bolt wrench, in an upwardly opening drive socket rotatable on a generally vertical axis in a drill box at the end of a pivot boom of a mine roof drill and bolter, includes a support adapted to be secured in position relative to the drill box, and at least one retaining member carried by the support for movement between a retracted position permitting insertion of the lower end of the tool in the socket and removal of the lower end of the tool from the socket and an operative position in which said member overlies a lower end portion of the tool to restrict upward movement of the tool; and means for effecting movement of said member between its said positions. Other objects and features will be in part apparent and in part pointed out hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation of a roof drill and bolter showing its drilling boom in its raised position for drilling a roof-bolt hole in the roof of the mine;

FIG. 2 is an enlarged horizontal section on line 22 of FIG. 1 (rotated showing a first embodiment of the apparatus of this invention for holding a rotary tool in a drive socket at the end of the boom;

FIG. 3 is a vertical section on line 3-3 of FIG. 2;

FIG. 4 is a view similar to FIG. 2 showing a second embodiment of the apparatus of this invention;

FIG. 5 is a vertical section on line 5-5 of FIG. 4;

FIG. 6 is a view similar to FIG. 2 showing a third embodiment of the apparatus of this invention;

FIG. 7 is a vertical section on line 77 of FIG. 6;

FIG. 8 is a view similar to FIG. 2 showing a fourth embodiment of the apparatus of this invention; and

FIG. 9 is a vertical section on line 9-9 of FIG. 8.

Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.

DESCRIPTION OF THE PREFERRED I EMBODIMENTS Referring to the .drawings, there is indicated at l a roof drill and bolter comprising a four-wheel vehicle movable in a mine on wheels 3 for drilling vertical holes in the mine roof R for roof bolts (not shown). These bolts, when inserted in the holes and tightened, compress the layers of rock in the mine roof to form a selfsupporting roof. In addition to drilling holes for the roof bolts, the roof drill and bolter is used to tighten the roof bolts. The vehicle has a drilling cradle generally indicated at 5 carrying a pivot boom 7 which is pivotally movable between a lowered position (not shown) in which the outer end of the boom is adjacent the mine floor and a raised position (as shown in FIG. 1) in which the outer end of the boom is adjacent mine roof R. A drill box 9 carrying a hydraulic motor 11 is mounted in a U-shaped frame 13 at the outer end of the drill boom. The drill box has a rotary drive socket 15 having an upwardly facing opening 17 of square crosssection for receiving a rotary tool generally indicated at 19, such as a roof drill (as shown in FIG. 1) or a roof bolt wrench, for rotation on a vertical axis. The upper portion of drill box 9 is constituted by a cover 20 (see FIGS. 2 and 3) which is bolted to the drill box by bolts 21. The cover has a cylindric center portion 22 which projects above the outer margin of the cover with the upper surface of the outer margin of the cover constituting an annular shoulder, as indicated at 23. Bolts 21 are arranged in a circle surrounding the cyclindric portion and are spaced equidistantly from one another. Drive socket 15 is located at the center of the cylindrical portion.

Drill boom 7 includes a pair of main boom members, each being indicated at 24, and each having its outer end pivotally connected to one side of frame 13, as indicated at 25. The drill boom further includes a pair of lower members, each being indicated at 26, and each being pivotally connected to frame 13 as indicated at 27 below the connection of the main members. The bottom ends of the main boom members and the lower members are pivotally supported by cradle in a manner permitting horizontal movement of the lower end of the drill boom as the drill boom is raised and lowered to maintain alignment between the axis of rotary tool 19 and the axis of the hole being drilled. Main boom members 24 and lower boom members 26 constitute a parallel linkage mechanism for maintaining the axis of the rotary tool vertical as the boom is raised and lowered. Drill boom 7 is raised and lowered by an extendible and retractable hydraulic cylinder unit 29 pivotally connected between the drill boom and the drill cradle. This cylinder unit is extendible at a desired rate to feed the drill into the mine roof as the hole is drilled, and is retractable to lower the drill boom for withdrawing the tool from the hole in the mine roof. The operation of the boom cradle 5, drill boom 7 and drill motor 11 is controlled by an operator who actuates hydraulic valves in a control valve bank generally indicated at 31 adjacent the forward end of drill cradle 5.

As shown in FIG. 3, rotary tool 19 typically includes a shank portion 33 of square cross-section at its lower end 35 (as shown in dotted lines) for reception in opening 17 of drive socket 15. The tool has an annular shoulder 37 which projects from its shank adjacent the lower end thereof for bearing against the upper face of the drive socket for transferring thrust loads from the tool to the drive socket.

In accordance with this invention, a safety retainer, generally indicated at 39, holds rotary tool 19 in drive socket to prevent the tool from flying out of the drive socket as it is rotated and to journal the shank of the tool to reduce the tendency of the outer end of the tool to whip" in the event the tool is rotated at high speed out of working engagement with the mine roof. As shown in FIGS. 2 and 3, retainer 39 includes a support plate 41 which is adapted to be bolted to cover of drill box 9 by bolts 21. This support plate is adapted to bear on shoulder 23 of the cover, and has a central opening 42 for receiving the cylindric portion 22 of the cover. First and second retaining or bearing members, respectively indicated at 43 and 45, are carried by the support plate for relative movement between a retracted or open position (as shown in phantom in FIG. 2) permitting insertion of the lower end 35 of tool 19 in socket 15 and removal of the lower end of the tool therefrom and an operative or closed position (as shown in solid lines) in which the retaining or bearing members are disposed on opposite sides of the tool and cooperate with each other to surround shank 33 of the tool and form a vertical bearing for the tool. A hydraulic cylinder and piston unit, generally indicated at 47, is provided for effecting relative movement of the retaining members between their retracted and operative positions. More particularly, bearing member 43 includes a pair of support members, each indicated at 49, extending up from support plate 41 for mounting a bearing half 51 adjacent tool 19. The support members are fixedly secured as by welding to the support plate and the position of bearing half 51 is thereby fixed relative to the support plate and to the vertical axis of the tool. Retaining member 45 includes a bell crank 53 having a bearing half 55 secured to one end thereof constituting its inner end. The bell crank has a bushing 57 intermediate its ends joumalled on a vertical bolt 59 secured to the support plate 41. Thus, retaining member 45 is free to pivot on bolt 59 toward and away from the fixed retaining member 43.

Bearing half 51 comprises a half-sleeve member 63 which is welded to the inner edges of both support members 49 with its inside cylindric surface coaxial with socket 15. A journal insert 65 of brass or the like is secured to the inside surface of the half-sleeve member to rotatably support shank portion 33 of the tool. Bearing half 55 is similar to hearing half 51 and comprises a half-sleeve member 57 welded to the inner face of hell crank arm 53 with its inside cylindric surface facing the tool. A journal insert 69 of brass or the like is carried by the half-sleeve member for engagement with the shank of the tool. Thus, when bearing member 45 is in its operative position, bearing half 55 cooperates with bearing half 51 to surround the tool and form a vertical bearing for the tool.

As shown in FIG. 3, the upper ends of bearing halves 51 and 55 are substantially at the same elevation. The lower end of bearing half 55, however, extends down below the lower end of bearing half 51 with the lower end of the former spaced above but closely adjacent flange 37 of the lower end of tool 19 when retaining member 45 is in its operative position thereby to restrict upward movement of the tool out of drive socket 15. The lower end of bearing half 51 is spaced above flange 37 a distance sufficient to permit insertion of the lower end of the tool in the drive socket and removal of the tool therefrom when retaining member 45 is in its open position. The hydraulic cylinder and piston unit 47 is supplied with hydraulic fluid under pressure via hydraulic lines 71 and 72 to effect in and out movement of its piston rod 73. The free end of piston rod 73 is pin-connected, as indicated at 74, to the outer end of bell crank 53, and the back end of the cylinder unit is pin-connected, as indicated at 75, to a mounting bracket 76 welded to support plate 41. A valve in control bank 31 controls the flow of hydraulic fluid in lines 71 and 72.

A variation of the above-described safety retainer is shown in FIGS. 4 and 5, this second retainer being indicated in its entirety at 77 to differentiate it from retainer 39. It comprises a support plate 78 which is adapted to be bolted to drill box 9 by bolts 21. This support plate has a central opening 79 for receiving cylindric portion 22 of drill box cover 20. First and second retaining or bearing members, respectively indicated at 80 and 81, are carried by support plate 78 for relative movement between a retracted or open position (as shown in phantom in FIG. 5) in which lower end 35 of tool 19 may be inserted in drive socket or removed therefrom, and an operative or closed position in which the retaining members are disposed on opposite sides of tool 19 and cooperate with each other to surround the shank of the tool to form a vertical bearing for the tool. Retaining member 80 (which is generally similar to bearing member 43 of retainer 39) is fixedly secured to the support plate, and includes a pair of support members 83, a half-sleeve member 85 welded to the inner ends of the support members and a journal bearing insert 87 secured within the inner cylindric surface of the half-sleeve member. These last-mentioned parts constitute a bearing half 89 which is similar to bearing plate and it carries a journal bearing insert 97 in its inner cylindric surface. The half-sleeve member and the insert together constitute a bearing half generally indicated at 99 which is similar to the bearing half 55 of retainer 39.

As shown in FIG. 5, the upper ends of the bearing halves 89 and 99 are substantially at the same elevation when bearing member 81 is in its operative position. The lower end of bearing half 99, however, extends down below the lower end of bearing half 89 so that the lower end of the former is spaced above but closely adjacent flange 37 of the lower end of tool 19 to restrict upward movement of the tool from drive socket 15. The lower end of bearing half 89 is spaced above flange 37 a distance sufficient to permit the tool to be inserted in the drive socket and to be removed therefrom when bearing member 81 is in its open position.

Bearing member 81 is swingable in a vertical plane toward and away from bearing member 79 by hydraulic cylinder and piston unit 101. This unit is similar to cylinder unit 47 heretofore described and includes a cylinder 103 and a piston rod 105. The cylinder is pinconnected to a bracket 107 extending from support plate78 by a bolt 109 and the free end of the piston rod is pin-connected to plate 91 by a boltlll. Hydraulic fluid is supplied to the cylinder unit by hydrauliclines 113 and 115 to effect in and out movement of the piston rod and the flow of hydraulic fluid to the cylinder is controlled by a valve in control valve bank 31.

A third variation of a retainer of this invention, indicated in its entirety at 117, is shown in FIGS. 6 and 7 to comprise a support plate 119 adapted to be secured by bolts 21 to drill box 9. A central opening 121 is provided in the support plate for receiving cylindric portion 22 of drill box cover 20. This retainer includes first and second retaining or bearing members 123 and 125 each pivotally mounted on the support plate on opposite sides of tool 19 for conjoint movement relative to each other between an open or retracted position (as shown in phanton in FIG. 7) in which both retaining members are clear of the tool permitting insertion of the lower end 35 of the tool into socket 15 and removal of the lower end of the tool therefrom, and a closedoperative position in which the retaining members cooperate with each other surrounding shank 33 of the tool forming a vertical bearing for the tool.

Bearing members 123 and are substantially identical and each includes an inverted L-shaped mounting member 127 having a vertically disposed lower leg 129 and a horizontally disposed upper leg 131. The lower end of the lower leg of each mounting member is pivotally connected, as indicated at 133, to a lug welded I to support plate 1 19. Each mounting member carries a bearing half 137 on the inner end of its upper leg. Each bearing half includes a half-sleeve member 139 which is welded to leg 131 and a journal insert 141 secured to the inner concave surface of the half-sleeve member for engagement with shank 33 of tool 19 to form a vertical bearing for the tool when the retaining members 123 and 125 are in their closed operative positions.

As shown in FIG. 7, bearing member 125 is pivotally movable in a vertical plane between its open retracted position and its closed operative position by a hydraulic cylinder and piston unit 143 which is pivotally connected between a lug 145 secured to vertical leg 129 of the retaining member and a mounting bracket 147 welded to support plate 119. The hydraulic cylinder unit includes a cylinder 149 and a piston rod 151 movable endwise therefrom. The back end of the cylinder is connected to mounting bracket 147 as indicated at 152 and the free end of the piston rod is pivotally connected to lug 145 by a clevis 153. This clevis is pinconnected to lug 145 by a bolt 154. Hydraulic fluid under pressure is supplied to the hydraulic cylinder by lines 155 and 156, and the in and out movement of the piston rod is controlled by a valve included in control valve bank 31.

Bearing member 123 is interconnected to bearing member 125 by a toggle linkage generally indicated at 157 at each side of the bearing members for effecting conjoint swinging movement of the bearing members between their open retracted position and their closed operative position in response to in and out movement of piston rod 151. Each of these toggle linkages includes a vertical guide member 159 secured to support plate 119, the guide member having a vertically disposed elongate slot 161 therein. A slide member or pin 163 is vertically movable within the guide slot. One end of a first toggle link 165 is pivotally connected as indicated-at 167 to vertical leg 129 of bearing member 123, and the other end of this first toggle link is pivotally connected to guide pin 163. One end of a second toggle link 169 is pivotally connected, as indicated at 171, to vertical leg 129 of bearing member 125, and the other end of the second toggle link is pivotally connected to the guide pin. As bearing member 125 is swung from its closed position to its open position, toggle links 169 cause guide pins 163 to move upwardly in slots 161 of their respective guides 169. This upward movement of the guide pins moves toggle links 165 to effect conjoint movement of bearing member 123 from its closed position to its open position. Similarly, as bearing member 125 moves from its open position to its closed position, bearing member 123 moves from its open position to its closed position.

A fourth embodiment of a retainer of this invention is shown in FIGS. 8 and 9 and is indicated in its entirety at 173. This retainer includes a support plate secured to cover 20 of drill box 9 by bolts 21. This support plate has an opening 177 for receiving the cylindric portion 22 of the cover and is cantilevered from the drill box for mounting a hydraulic cylinder and piston unit 179 for purposes as will appear. A stationary retainer guide assembly, generally indicated at 180, is spaced above support plate on spacer bushings 181 which surround bolts 21. These bolts secure the guide assembly to drill box cover 20. Guide assembly 180 includes a plate 183 overlying drill box 9 having a central opening 185 to permit the lower end 35 of a tool 19 to be inserted in and removed from socket 15. This plate is counterbored as indicated at 187 to provide a recess for the head of each bolt 21 so that the bolt heads are recessed below the level of the upper surface of the plate. A pair of angle members, each generally indicated at 189, is welded to plate 183. These angle members are on opposite sies of the plate from one another and each has a vertical leg 191 extending above the plate and an inwardly extending horizontal leg 193 spaced above the upper surface of the plate. A slidable retaining member or plate 195 is slidably retained on the upper surface of plate 183 by these horizontal legs in a manner permitting horizontal sliding movement of the plate between a retracted position (shown in phantom in FIG. 8) permitting insertion of the lower end of the tool in the drive socket and removal of the tool therefrom and a closed operative position. The retaining plate has a notch 197 in one edge thereof adjacent tool 19 for enabling the retaining plate to surround shank 33 of the tool and to overlie shoulder 37 of the tool when the retainer plate is in its operative position to restrict upward movement of the tool out of the drive socket.

Retainer plate 195 is slidably moved between its operative and retracted positions by the hydraulic cylinder unit 179 which includes a cylinder 199 pivotally connected to the cantilevered portion of support plate 175 as indicated at 201 and a piston rod 203 movable endwise from the cylinder. The free end of the piston rod is pivotally connected to the retainer plate as indicated at 205. The cylinder unit is supplied with hydraulic fluid under pressure by hydraulic lines 207 and 209. The flow of hydraulic fluid to these lines is controlled by a valve included within the control valve bank 31.

As shown in FIG. 9, retainer 173 projects above the level of socket only a relatively short distance (compared to retainer 77, for example) and thus enables substantially all of the length of tool 19 .to be used to drill bolt holes in roof R. This is particularly advantageous in low coal" mining applications (i.e., where the height of the mine is low).

Since the operation of the four retainers herein described (i.e., retainers 39, 77, 117 and 173) is essentially the same, only the operation of retainer 39 shown in FIGS. 2 and 3 will be described in detail. With roof bolt drill and bolter 1 moved into position within the mine, drill boom 7 is lowered and an appropriate control valve within control valve bank 31 is actuated to energize hydraulic cylinder unit 47 to efi'ect rotation of bell crank arm 53 about bolt 59 to move bearing member 45 from its closed position to its open position. The lower end 35 of a roof drill tool 19 is inserted in opening 17 of drive socket l5 and the hydraulic cylinder unit is reversely energized to effect movement of bearing member 45 from its open position to its closed position wherein bearing half 55 cooperates with bearing half 51 to surround the shank portion 33 of the drill to form a vertical bearing for the drill. The drill boom is raised until the tip of the roof drill contacts mine roof R and then hydraulic motor 11 is hydraulically energized to drive drill box 9 and the roof drill socketed therein. Upon completion of the drilling of the roof bolt hole to a desired depth in the mine roof, the drill is withdrawn from the roof bolt hole by lowering the drill boom. It will be understood that if the drill binds within the hole, the lower end of bearing member is spaced adjacent to shoulder 37 for engagement therewith and enables the tool to be forcibly withdrawn from the hole by the lowering of the boom. Bearing member 45 is then moved from its operative position to its open position to permit the drill to be removed from the drive socket and to permit a roof bolt wrench (not shown) to be inserted in the socket. Bearing member 45 is then moved from its retracted position to its operative position to surround the roof bolt wrench and the drill boom is then raised so that the roof bolt wrench is in engagement with a roof bolt which has been inserted in the roof bolt hole. The drill motor is again energized and the roof bolt wrench is rotated to tighten the roof bolt in the hole.

It will be noted that the retainers of this invention move between their retracted and operative positions with sufficient speed to permit rapid insertion of a tool 19 in drive socket l5 and to permit the rapid removal of the tool therefrom.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

l. A roof drilling and bolting apparatus comprising vertically movable boom means, means carried by said boom means defining an upwardly opening drive socket adapted to receive the lower end of a tool to be driven by the apparatus, and retainer means carried by said boom means for retaining a tool which includes a collar on its lower end portion in said drive socket, said retainer means comprising a plurality of retainer members relatively movable between relative positions permitting insertion of the lower end of such a tool in said drive socket and relative positions wherein said retainer members cooperate to extend around such a tool and at least one thereof overlies the collar on the lower end portion of the tool to restrict upward movement of the tool, the mounting of said retainer members and said drive socket defining. means to said boom means preventing movement of said drive socket relative to said retainer members at least with said retainer members in their said second mentioned relative positions, and means for effecting relative movement of said retainer members between their said first and second mentioned relative positions said drive socket defining means comprising a drill box, said retainer means further comprising supporting means carried by said boom means and in fixed relationship with said drill box, and said retainer members being supported by said supporting means.

2. A roof drilling and bolting apparatus according to claim 1, wherein said drill box is provided with a peripheral shoulder, and said supporting means comprises a support plate affixed to said shoulder.

3. A roof drilling and bolting apparatus according to claim 1, wherein said drill box comprises an upwardly extending portion and a shoulder extending around said upwardly extending portion, and ssai supporting means comprises a support plate having an opening receiving said upwardly extending portion of said drill box and affixed to said shoulder thereof.

4. A roof drilling and bolting apparatus according to claim 1, wehrein one of said retainer members is fixed relative to said supporting means, and a second of said retainer members is movable relative to said supporting means towards-and-away from said one of said retainer members.

5. A roof drilling and bolting apparatus according to claim 4, wherein said second of said retaining members is pivotally mounted for movement in a horizontal plane, and said relative movement effecting means comprises fluid operated cylinder-and-piston means connected to said second of said retaining members for so pivoting the latter.

6. A roof drilling and bolting apparatus according to claim 4, wherein said second of said retaining members is pivotably mounted for movement in a vertical plane, and said relative movement effecting means comprises fluid operated cylinder-and piston means connected to said second of said retaining members for so pivoting the latter.

7. A roof drilling and bolting apparatus according to claim 4, wherein said second of said retainer members extends downwardly below the lower end of said one of said retainer members for restricting upward movement of the tool when said retainer members are in their second mentioned relative positions.

8. A roof drilling and bolting apparatus according to claim 1, wherein said retainer members are each movable towards-and-away from the other, said relative movement effecting means comprises fluid operated cylinder-and-piston means connected to one of said retainer members for moving such retainer members, and said retainer means comprises linkage means interconnecting said retainer members to cause movement of said one retainer member to provide enjoined movement of the other thereof.

9. In a roof drilling and bolting apparatus, vertically movable boom means, means carried by said boom means defining an upwardly opening drive socket adapted to receive the lower end of a tool to be driven by the apparatus, and retainer means carried by said boom means for retaining in said drive socket, a tool which includes a collar on its lower end portion said re tainer means comprising at least one retainer member movable between a retracted position permitting insertion of the lower end of such a tool in said drive socket and an operative position wherein said retainer member overlies a lower end portion of the tool to restrict upward movement of the tool, and the mounting of said retainer member and said drive socket defining means to said boom means preventing vertical movement of said drive socket relative to said retainer member at least with said retainer member in its operative position said drive socket defining means comprising a drill box, said retainer means further comprising supporting means carried by said boom means and in fixed relationship with said drill box, and said retainer members being supported by said supporting means.

10. A roof drilling and bolting apparatus according to claim 9, further comprising means connected to said retainer member for moving said retainer member between its said retracted and operative positions.

1 l. A roof drilling and bolting apparatus according to claim 9, wherein said drill box comprises an upwardly extending portion and a shoulder extending around said upwardly extending portion, and said supporting means comprises a support plate having an opening receiving said upwardly extending portion of said drill box and affixed to said shoulder thereof.

12. In a roof drilling and bolting apparatus, vertically movable boom means, means carried by said boom means defining an upwardly opening drive socket adapted to receive the lower end of a tool to be driven by the apparatus, and retainer means carried by said boom means for retaining in said drive socket, a tool which includes a collar on its lower end portion said retainer means comprising a plurality of retainer members relatively movable between relative positions permitting insertion of the lower end of such a tool in said drive socket and relative positions wherein said retainer members cooperate to extend around such a tool and at least one thereof overlies the lower end portion of the tool to restrict upward movement of the tool, and the mounting of said retainer members and said drive socket defining means to saidboom means preventing vertical movement of said drive socket relative to said retainer members at least with said retainer members in their said second mentioned relative positions said drive socket defining means comprising a drill box, said retainer means further comprising supporting means carried by said boom means and in fixed relationship with said drill box, and said'retainer members being supported by said supporting means. 

1. A roof drilling and bolting apparatus comprising vertically movable boom means, means carried by said boom means defining an upwardLy opening drive socket adapted to receive the lower end of a tool to be driven by the apparatus, and retainer means carried by said boom means for retaining a tool which includes a collar on its lower end portion in said drive socket, said retainer means comprising a plurality of retainer members relatively movable between relative positions permitting insertion of the lower end of such a tool in said drive socket and relative positions wherein said retainer members cooperate to extend around such a tool and at least one thereof overlies the collar on the lower end portion of the tool to restrict upward movement of the tool, the mounting of said retainer members and said drive socket defining means to said boom means preventing movement of said drive socket relative to said retainer members at least with said retainer members in their said second mentioned relative positions, and means for effecting relative movement of said retainer members between their said first and second mentioned relative positions said drive socket defining means comprising a drill box, said retainer means further comprising supporting means carried by said boom means and in fixed relationship with said drill box, and said retainer members being supported by said supporting means.
 2. A roof drilling and bolting apparatus according to claim 1, wherein said drill box is provided with a peripheral shoulder, and said supporting means comprises a support plate affixed to said shoulder.
 3. A roof drilling and bolting apparatus according to claim 1, wherein said drill box comprises an upwardly extending portion and a shoulder extending around said upwardly extending portion, and ssai supporting means comprises a support plate having an opening receiving said upwardly extending portion of said drill box and affixed to said shoulder thereof.
 4. A roof drilling and bolting apparatus according to claim 1, wehrein one of said retainer members is fixed relative to said supporting means, and a second of said retainer members is movable relative to said supporting means towards-and-away from said one of said retainer members.
 5. A roof drilling and bolting apparatus according to claim 4, wherein said second of said retaining members is pivotally mounted for movement in a horizontal plane, and said relative movement effecting means comprises fluid operated cylinder-and-piston means connected to said second of said retaining members for so pivoting the latter.
 6. A roof drilling and bolting apparatus according to claim 4, wherein said second of said retaining members is pivotably mounted for movement in a vertical plane, and said relative movement effecting means comprises fluid operated cylinder-and-piston means connected to said second of said retaining members for so pivoting the latter.
 7. A roof drilling and bolting apparatus according to claim 4, wherein said second of said retainer members extends downwardly below the lower end of said one of said retainer members for restricting upward movement of the tool when said retainer members are in their second mentioned relative positions.
 8. A roof drilling and bolting apparatus according to claim 1, wherein said retainer members are each movable towards-and-away from the other, said relative movement effecting means comprises fluid operated cylinder-and-piston means connected to one of said retainer members for moving such retainer members, and said retainer means comprises linkage means interconnecting said retainer members to cause movement of said one retainer member to provide enjoined movement of the other thereof.
 9. In a roof drilling and bolting apparatus, vertically movable boom means, means carried by said boom means defining an upwardly opening drive socket adapted to receive the lower end of a tool to be driven by the apparatus, and retainer means carried by said boom means for retaining in said drive socket, a tool which includes a collar on its lower end portion said retainer means comprising at least one retainer member movabLe between a retracted position permitting insertion of the lower end of such a tool in said drive socket and an operative position wherein said retainer member overlies a lower end portion of the tool to restrict upward movement of the tool, and the mounting of said retainer member and said drive socket defining means to said boom means preventing vertical movement of said drive socket relative to said retainer member at least with said retainer member in its operative position said drive socket defining means comprising a drill box, said retainer means further comprising supporting means carried by said boom means and in fixed relationship with said drill box, and said retainer members being supported by said supporting means.
 10. A roof drilling and bolting apparatus according to claim 9, further comprising means connected to said retainer member for moving said retainer member between its said retracted and operative positions.
 11. A roof drilling and bolting apparatus according to claim 9, wherein said drill box comprises an upwardly extending portion and a shoulder extending around said upwardly extending portion, and said supporting means comprises a support plate having an opening receiving said upwardly extending portion of said drill box and affixed to said shoulder thereof.
 12. In a roof drilling and bolting apparatus, vertically movable boom means, means carried by said boom means defining an upwardly opening drive socket adapted to receive the lower end of a tool to be driven by the apparatus, and retainer means carried by said boom means for retaining in said drive socket, a tool which includes a collar on its lower end portion said retainer means comprising a plurality of retainer members relatively movable between relative positions permitting insertion of the lower end of such a tool in said drive socket and relative positions wherein said retainer members cooperate to extend around such a tool and at least one thereof overlies the lower end portion of the tool to restrict upward movement of the tool, and the mounting of said retainer members and said drive socket defining means to said boom means preventing vertical movement of said drive socket relative to said retainer members at least with said retainer members in their said second mentioned relative positions said drive socket defining means comprising a drill box, said retainer means further comprising supporting means carried by said boom means and in fixed relationship with said drill box, and said retainer members being supported by said supporting means. 